Electric switch.



F. A. LUNDQUIST.

ELECTRIC SWITCH.

APPLICATION FILED SEPT. 1.3. 1916.

Patented Aug. 28, 1917.

2 SHEETS-SHEET I.

Frank A. Lundquisf.

i) v W F. A. LUNDQUIST.

ELECTRIC SWITCH.

APPLICATION man SEPT. :3. 1916.

1,238, 1 62 Patented Aug. 28, 1917.

2 SHEETS-SHEET 2.

/m e/? for: Fran/r 14. Lundqu/si Ar/y UNITED STATES PATENT OFFICE.-

FRANK A. LUNDQUIST, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COM- PANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ELECTRIC SWITCH.

Application filed September 13, 1916.

To all whom it may concern: 7

Be it known that I, FRANK A. LUNDQUIST, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Electric Switches, of which the following is a full, clear, concise, and exact description.

This invention relates to electric switches useful in automatic and semi-automatic telephone systems.

One object of the invention is to provide a switch wherein a plurality of movable terminal strips are available to a plurality of rotary switches, which, with the terminal strips, form a switch unit.

Another object is to provide a switch in which a brush set arranged to engage terminals of a contact bank, is held out of engaging position except on forward movement of the switch, incident to the location of a desired terminal, and is withdrawn so as to be free of other terminals when returning to normal.

A further object is to retain the brush set out of engaging position during forward movement until a desired group in the contact bank has been reached.

Referring to the drawings, Figure 1 shows a plan view of a switch embodying one form of the invention, and showing a single one of the rotary switches used; Fig. 2 is a side elevation thereof; Fig. 3 is a cross-sectional view on the line 33 of Fig. 2, showing the arrangement of an ofi-normal contact; Fig. 4 shows a modification of the switch when it is to be used as a line finder; Fig. 5 is a plan view of another form of switch embodying the invention, together with the circuit for operating the same; Fig. 6 is the elevation thereof; and Fig. 7 is adetailed view of the mechanism operating the brush set in group selection.

The switch shown in Figs. 1 and 2 comprises a vertical stationary shaft 10, which carries a plurality of rotary switches 11. The switches 11 are equally spaced on the shaft 10, and when operated, sweep over an arcuate contact bank 12. The bank 12 is made up of a plurality of vertically arranged terminal units or bars 13, common to all the switches 11. The terminal unit 13 comprises conducting strips 14 and 15, secured on opposite sides of an insulating strip 16. The insulating strip carries studs Specification of Letters Patent.

Patented Aug. 28, 1917.

Serial No. 119,810.

17 and 18, pivoted in and slidable in the upper and lower frame pieces 19 and 20, respectively, of the contact bank 12. The terminal unit is somewhat less in length than the distance between the upper and lower frames 19 and 20, and is normally in the position shown in Fig. 2. The conducting strip 15 has a plurality of short horizontal projections 21 thereon, equal in number to the switches 11, and spaced apart a distanceequal to that between the switches 11. The conducting strip 1-1 is provided with similar projections 22, which are somewhat longer and arranged slightly below projections 21. The lower end of the terminal unit carries a horizontally arranged extension 23, which presses upon, and is preferably insulated from a spring contact 2 1, which serves to keep the terminal unit in the position shown in Fig. 3. lVhen a unit is rotated incident to the taking thereof to extend the call to succeeding apparatus if used as a line switch, or from a calling line if used as a line finder, the spring contact 24 is moved to engage a contact 25, and serves to close a circuit for an operating magnet 26, individual to the terminal unit, over a circuit extending from ground, contact 25, spring contact 2%, conductor 27, operating magnet 26 to grounded battery. The stud 18 extends below the frame 20, and bears upon one end of a pivoted armature 28, controlled by the magnet 26. On energization of magnet 26, the armature 28 pulls up to raise its terminal unit for a purpose to be later described.

Each of the switches 11 rests on a collar 29 secured on the shaft 11, and comprises a gear wheel 30, readily rotatable on said shaft. The switches 11 each have a brush support 31 mounted directly above the wheel 30, and 9 rotatably mounted on the shaft 10. Suitable means, such as a friction bushing 32, is, however, provided so that it tends to lag behind the wheel 30 on movement thereof in either direction. The support 31 carries a pair of brackets 33, on which the member 31 is longitudinally slidable. The member 3 1 has a lateral extension 35, on which spring brushes 36 and 37 are mounted. These brushes are separated by insulation, and the upper brush 36 has its engaging portion extending slightly beyond and in the rear of the brush 37, so as to engage the projections 21 of the terminal unit. The gear wheel 30 has an arm 38 thereon, to which is pivoted a rod 39 pivoted in turn to the extension 35 of the sliding member 34.

To efl'ect movement of the switch 11, a rack is provided and connected by rod 41 to a piston 42, slidable in a cylinder 43, vented at one end. An air pipe 44 leads from the other end of the cylinder 43 to an air valve 45, from whence a pipe 46 leads to any suitable source of compressed air. The valve is operated on attraction of a pivoted armature 47, controlled by a mag net 4.8. On energization of the magnet 48, air is supplied to the cylinder 43 to force the piston outwardly and operate the switch, while on deenergization of the magnet 48, the valve 45 permits the cylinder to exhaust to air, while a spring 49 withdraws the rack 40 to normal position.

The switch shown may be used either as a line switch or as a line finder. If used as a line switch, a subscribers line would be connected to the brushes 36 and 37, and the terminal units 13 would have trunks leading to succeeding apparatus to accomplish the extension of the call; while, if used as a line finder, the subscribers line would be associated with the terminal units and the trunk lines extend from the brushes 36 and 37. Owing to the small space occupied by the individual switches 11 and the type of contact bank, line finders of large capacity and of small size can be obtained.

If the switch is used as a line switch, the magnet 48 will be individual to the line to which its switch 11 is allotted, and this magnet will be energized when the subscriber initiates a call. If the switch isused as a line finder, any suitable means actuated upon initiation of a call could be used to energize the magnet 48 of an idle finder switch 11, which would thereupon hunt for the calling line. In this case, the terminal units would have three positions, for example: a lowermost position, in which the projections thereon could not be engaged by the switches 11; a middle position to which the unit would be moved when the line originates a call, and in which the projections would be positioned for engagement by the switches 11; and a third or busy position to which it would be moved by a magnet 26 when seized, and in which position the projection would not obstruct the movement of the other switches 11. Such a modification is shown in Fig. 4 where a magnet -would extend through the magnet 48 of one of the switches 11 to operate the same.

The operation of this form of invention when used as a line switch is as follows: Vhen a subscriber initiates a call, the magnet 48 is energized, whereupon the valve 45 admits compressed air to the cylinder 43 and forces the piston 42 forward, the rack 40 following. The wheel 30 is rotated to the left, which moves the arm 38 thereon so as to force the brushes 3(3 and 37 outwardly into position to engage the first idle terminal unit 13 encountered. The support 31 remains in normal position, due to its frictional connection on the shaft 10, until the member 34 has been moved to its forward limit, whereupon the wheel 30 and support 31 move as a unit. The engaging portions of the brushes 30 and 37, on encountering the terminals 21 and 22 of the first idle terminal unit 13, would rotate the terminal unit andclose the circuit of its operating magnet 26. The magnet 26 would then raise the terminal unit against the overhanging engaging portions of the contact springs, and move the other projections 21 and of that unit so that the movement of other switches 11 would not be interfered with. A better contact is also provided between the brushes 3-30 and 37, and the projections 21 and 22 of the terminal units, due to this ope 'ation. On completion of conversation, the magnet 48 is deenergized, and the air valve 45 operates to shut off the compressed air and release the air previously confined in the cylinder. The spring 49 thereupon returns the rack 40 to normal. This rotates the wheel 30 to the right, while the support 31 lags until the action of the extension 38 and rod 39 on the member has withdrawn the brushes to their inner limit. The wheel 30 and support 31 then move as a unit and continue until the support 31 engages a. stop 50, carried on the stationary part of the switch frame. As soon as the brushes are disengaged from the terminal unit 13, the spring contact 24 rotates the unit to normal, and deenergizes the operating magnet 26, whereupon the unitdrops to its normal position.

In the form of invention shown in Figs. 5, 6 and 7, the terminal units are of the same construction as shown in. Figs. 1, 2 and 3, but these units, instead. of being in a single group, are arranged in a plurality of groups, and the brush set is arranged so as to search for the terminal unit only in a selected group.

A shaft 100 is provided and kept in constant rotation by means of a driven pinion 101, engaging a gear wheel 102 fixed on the shaft 100. A plurality of rotary switches 103 are spaced on the shaft 100 and rotatably mounted thereon. Cach switch 103 normally rests on a shoulder 104 on the shaft 100, and has ajaw clutch 105 individual to it, carried upon the shaft for a purpose hereinafter set forth. Each switch 103 has a shouldered hub 10G freely rotatable 0n the shaft 100, and carrying an escapeinent wheel 107, having a plurality of pins 108, equal in number to the groups in the contact bank spaced thereon. This wheel 107 normally tends to rotate under the action of a spiral spring 109, which has one end secured to a stationary part of the switch structure, and the other end secured to the wheel 107. A detent 110, carried on one end of a pivoted armature 111, controlled by a magnet 112, normally engages one of the pins 108 to prevent rotation of the wheel 107. On op eration of the magnet 112, the wheel 107 escapes one step. The hub 106 extends some distance upon the wheel 107, and carries a support 113 freely rotatable thereon. The support and wheel are normally in the position shown in Fig. 5, in which an insulated stud 111 on the wheel 107 is engaged by a spring contact 115 on the support. The support and wheel are coupled by a spiral spring 116 of less strength than the spring 109, so that on escapement of the wheel 107, the support 113 lags somewhat and only catches up with the wheel after the same has stopped. The support 113 carries brackets 117 at its outer end, within which a member 118 is slidable. The member 118 carries a plurality of spring contact brushes 119 and 120, identical with the brushes 36 and 37 of the switch first described. The sliding member 118 has an extension 121 to which a bar 122 is pivotally mounted, this bar being slidable in a guide 123 on support 113. Be tween this guide and the extension 121 is a spring 121, tending to hold the brushes inwardly, out of engaging position. The inner end of the operation bar 122 is resilient, and tends to move upwardly, but is normally held in its lowermost position by a finger 125 on a curved lever 126. The lever 126 is pivoted on the support 113, and has an arm 127 arranged to engage a stop 128 on the support 113, under the influence of a spring 129, as best shown in Fig. 1n the normal position of the switch, as shown in Fig. 5, however, a pin 130, carried on the upper surface of the wheel 107, engages this arm 127 to position the finger 125, as shown in Fig. 0n escapement of the wheel 107, however, the support 113 lags behind, and permits the lever 126 to be retracted so that the finger 125 is positioned back of a shoulder 131 on the bar 122. The bar 122 thereupon springs upwardly and when the support 113 overtakes the wheel 107, the pin 130 operates on the lever 126, so that the finger 125 forces the bar 122 outwardly, carrying the brushes 119 and 120 into position to engage the terminal units on subsequent escapement. The upward movement of the bar 122 is limited by av stop finger 153 carried by and rotatable with the support 113, and the shoulder 131 has a depth greater than the thickness of the finger 125. When the bar 122 is forced outwardly by the action of the finger 125, the inner end of the bar.122 springs upwardly, positioning a second shoulder 152 on the bar 122 against the stop finger 153. This holds the brushes 119, 120 in engaging position until the release of the switch.

111 using this switch for trunk selection, the line leading from a preceding finder would be connected to the brushes 119, 120, of the switch 103 allotted thereto. On first connection of this switch, ground from the preceding apparatus would be put on the line 131 to energize the relay 135. This re lay 135, on pulling up, will complete at its front contact a circuit for the escapeinent magnet 112. This circuit extends from grounded battery, armature and front contact of relay 135, conductor 136, conductor 137. spring 138, contact 139 to ground. This positions the brushes 119, 120 in operative relation to the first group of terminals, and subsequent operation will cause the switch 103 to step over the succeeding groups. 1 branch circuit is also completed therefrom to a release magnet 110, this magnet being slow in deenergizing, so as to be uninfluenced by the momentary interruptions in its circuit, incident to the sending of the call inipulses usual in automatic telephony. The operation of the magnet 110 and the release mechanism controlled thereby will be later described. The sending of the impulses over the conductor 131 results in momentary interruptions of the circuit for the relay 135, which thus operates the escapement magnet 112 to step the wheel 107 the desired number of steps. 611 the first de'elnergization of relay 135, a circuit is completed for a circuitcontrolling switch magnet 112, this magnet being slow to release. A. stud 113, carried on the periphery of the wheel 107, controls an off-normal contact 111, which is closed as soon as the wheel 107 is rotated. This stud 113 also normally engages a catch 115, carried on a pivoted armature 116 under the control of the magnet 112. On the first deenergization of relay 135, the armature 116 is pulled up, positioning the catch 115 beneath the spring 138, ready to move said spring on deenergization of the magnet 112. This circuit extends from grounded battery, armature and rear contact of relay 135, conductor 117, magnet 112, off-normal contact 111, conductor 118, spring 138, contact 139 to ground. The magnet 112 remains energized until the magnet 135 holds up for a longer interval at the termination of the series of impulses, whereupon it is deenergized and the spring 138 is moved out of engagement with the lower contacts and into engagement with the upper contact by the catch 115. The support 113, on reaching normal position with regard to the wheel 107, completes a circuit from ground, stud 11 1-, spring 115, conductor 151, contact 150, spring 138, conductor 137, escape magnet 112, conductor 136, front contact and ar1na ture of relay 135 to grounded battery.

The operative movement of the brushes 119 and 120 is effected by the finger 125, while the brushes are passing the space between adjacent groups of terminals, and stops them just short of engagement with the first terminal unit in the desirec group.

The support 113, on catching up with the wheel 107, directly after the change-over closes a circuit over the path n-eviously described to the magnet 112, escaping the wheel, 107 another step. The finger 125 moves out ol. engagement with the shoulder 131., but the brushes are not moved inwardly as the stop piece 153 engages the shoulder 152 on the bar 122, and prevents inward movement at this time. The support 113 follows the wheel until the brushes 119, 120 engage the terminal unit in the same manner as in the switch shown in Figs. 1 t0 3, closing a circuit to an elevating magnet to move the terminal unit longitudinally to allow freedom of movement of the other switches 103.

The hub 106 carries a pin 154:, which in the normal rotary position of the wheel 107, "Forces an elevating pawl 155 out of engagement with the lower edge ot the hub. This pawl, 155 is pivoted to one end of an armature 156 and spring-pressed to normally engage the lower edge of the hub 106. The spring 157, secured to the armature 156, tends to move the wheel 107 upwardly when the pawl 155 engages the hub 106. A slowrelease magnet 140, however, controls the armature 156, and this magnet is energized as soon as the switch is taken for use, and remains so until it is desired to disengage the brushes 119 and 120 from the terminal unit at the end of a conversation. The relay 135, "tailing oil", accomplishes this deenergization. The armature 156, in returning to normal, carries the hub 106 upwardly to bring a aw clutch 158, secured to the upper end of the hub, into engagement with the jaw clutch 105, which is in constant rotation.

A member 159 is rigidly secured to a stationary part of the frame 160 and loosely surrounds the hub 106. This member is circular and of a size to overlie an inwardly extending portion 161 on the bar 122, with out, however, extending over the finger 125 and stop piece 153. Thus, when the hub 106 and the parts mounted thereon are moved upwardly, the member 159 engages the extension 161 and forces it out of engagement with the finger 125 and stop piece 153. The brushes are thereupon drawn inwardly under the influence of the spring 121.

On reaching normal, the pin 15 lforces the pawl 155 out of engagement with the hub 106, whereupon it drops to its lower position,

disengaging the jaw clutch. The pin 143, in reaching normal, discngages the catch 115 from the spring 138, and opens the oil'- normal contact 1H. A stop pin 163 on a stationary part of the switch frame, insures the stopping of the switch in normal position, while the detent 110, engaging the pin 108, prevents escapement of the wheel 107. It is obvious that the spring 10$) is rewound in this operation.

The operation of the switch is as follows: a"; subscriber having removed his receiver, and a line finder, not shown, having located the calling line, a. trunk (LClOlltllllQ' from the line finder to the brushes ot a switch 102-1. extends the calling line thereto, ready to seize a, trunk leading to other apparatus through which. the call is to be extended. The relay 135, individual to the switch 103 tali n, is energized, completing a circuit for the magnet 112, as previously traced. The magnet 1-10 is also energized at this time and attracts its arn'iature, thus preventing the hub 106 being moved upwardly on movement of the wheel 107. On movement of the wheel. 107, the off-normal contact 114 is closed, preparing a circuit for the magnet 1 1-2, and leaving the catch 115 tree to opcrate. Short interruptions oi the circuit. the number depending on the number oi, the desired group, result in stopping the wheel 107 to such group. The first deiinergization ol relay 135 closes a. circuit for the magnet 1 12, whose armature 116 carries the catch 115 into engagement with the spring 138, ready to carry the same upwardly on deenergization of the magnet This magnet 1. 1:2, being slow to release. holds up until the end of the first series of impulses. Thereupon the armature 146 falls off, and the spring 138 breaks contact with the lower contacts, and engages the contact 150. \Vhen the support 113 a 'iprozu-hcs the stop position oi the wheel 107, the brushes 11!) and 120 are moved outwardly, as previously described, and when the pin 114- cngagcs the spring 115, the magnet 112 is energized over the circuit previously described. This escapes the ivhecl 107 another step, and the support 113 follows with the brushes held out, until the first idle terminal unit in the selected group is engaged. lVhen the brushes engage the projections on the terminal unit. they rotate the same, closing the circuit to the elevating magnet, thus moving the terminal unit to busy position, in which the projections will not interfere with the movement of other switches. The line is then extended in the customary manner and conversation takes place. On completion, the relay 135 falls otY. dei nergizing magnet 110. and armature 156 operates to raise the hub 106 and engage the jaw clutches 105 and 158. The bar 122, carrying the brushes, returns to normal as described, and the switch rotates to normal position, whereupon the catch 145 is disengaged and the off-normal contact late opened to place the switch structure in normal position ready for subsequent operation.

What is claimed is:

1. In a switching device, a plurality of movable contacts, a plurality of longitudinally movable terminal bars common to, said movable contacts for engagement thereby, means to position said bars for engagement by said movable contacts, and means operated on engagement of a movable contact with a bar to move said bar longitudinally so that other of said movable contacts will not engage therewith.

2. In a switching device, a plurality of rotary switches, a plurality of longitudinally movable terminal bars common to said rotary switches for engagement thereby, means to position said bars for engagement by said rotary switches, and means operated on engagement of a rotary switch with a bar to move said bar longitudinally so that other of said rotary switches will not en gage therewith.

3. In a switching device, a plurality of movable switches, a plurality of bars having longitudinal movement, and means to move said bars longitudinally on seizure thereof by any of said movable switches.

41. In a switching device, a plurality of rotary switches, a plurality of bars having longitudinal movement, and means to move said bars longitudinally on seizure thereof by any of said rotary switches.

5. In a switching device, a plurality of movable switches, a plurality of bars having rotary and longitudinal movement, said bars being rotated on seizure by a movable switch, and means operated on rotation of said bars to move the same longitudinally.-

6. In a switching device, a plurality of rotary switches, a plurality 01 bars having rotary and longitudinal movement, said bars being rotated on seizure by a rotary switch, and means operated on rotation of said bars to move the same longitudinally.

7. In a switching device, a plurality of movable switches, a brush for each of said movable switches, a plurality of bars having longitudinal movement, and means operated on engagement of a movable switch with a bar to move said bar longitudinally to better the connection with the brush carried by the engaging movable switch.

8. In an electric switch, a plurality of terminals, a brush carriage, a brush movable relative to said carriage to engage with said terminals, means actuated on the forward movement of said brush carriage to move the brush to terminal-engaging position, and means to retract said brush from terminal engaging. position to prevent contact with any of said terminals during the return of the brush carriage to normal.

9. In an electric switch, a plurality of terminals, a brush carriage, a brush movable relative to said carriage to engage said terminals, means to move said brush into position to engage desired one of said terminals, and means to normally position said brush out of terminal-engaging position during movement of said brush carriage.

10. In an electric switch, a plurality of terminals, a rotatable brush carriage, a brush movable relative to said carriage to engage said terminals, means operated on rotary movement of the brush carriage in one direction to move said brush into terminal-engaging position, and means to disengage said brush from a terminal and move said brush out of terminal-engaging position on rotary movement of said brush carriage in another direction.

11. In an electric switch, a plurality of terminals arranged for rotary and longitudinal movement, a rotary switch to engage with said terminals and rotate the same, electromagnetic means to move said terminals longitudinally, and means controlling said electromagnetic means and actuated by the rotary movement of said terminals.

12. In an electric switch, a plurality of terminals arranged for rotary and longitudinal movement, a rotary switch to engage with and rotate said terminals, electromagnetic means individual to said terminals to move the same longitudinally, and means individual to said terminals controlling their respective electromagnetic means and actuated by rotary movement of said terminals.

13. In an electric switch, a plurality of groups of terminals, said groups being spaced apart, a movable contact to engage said terminals, means to normally position said contact so that it will pass said terminals without engaging therewith, and means to move said contact to engage with said terminals, such movement taking place while the contact is passing a space between said groups.

1 1. In an electric switch, a plurality of groups of terminals, a movable contact to engage said terminals, means to move said contact to any desired group, means to po sition said contact so that it will not touch the terminals of undesired groups, and means to move said contact to terminal-engaging position immediately prior to the contact reaching the desired group.

15. In an electric switch, a plurality of groups of terminals, said groups being spaced apart, a movable contact to engage said terminals, means to move said contact to any desired group, means to position said contact so that it will not touch the terminals of undesired groups, and means to movesaid contact to terminal-engaging position, such movement taking place while the contact is passing the space between a preceding group and the desired group.

16. In an electric switch, movable contacts, a rotatable support therefor, a stop for determining the stopping position of said support, means for moving said stop to the desired position, and means to cause said support to move toward its set position simultaneously with the movement of said stop-moving means.

' 17. In an electric switch, a plurality of terminals, a contact to engage said terminals, a rotatable support on which said contact is movable, rotatable stop means movable in advance of said support for determining the stopping position of said support, means normally holding said contact out of engaging position with said terminals on movement of said support, and means to move said contact to terminal-engaging position when the support reaches a position determined by said stop means.

18. In an electric switch, a plurality of groups of terminals, a contact'to engage said terminals, a rotatable support on which said contact is movable, means to stop the support at any desired group, means normally holding said contact out of engaging position with said terminals on movement of said support, means to move said contact to terminal-engaging position when the support reaches the desired group, and means actuated on the support reaching said stop means to move said contact to engage it with a terminal in the desired group.

19. In an electric switch, a plurality of groups of terminals, a contact to engage said terminals, a rotatable support on which said contact is movable, means to stop the support at any desired group, means normally holding said contact out of engaging position with said terminals on movement of said support, means to move said contact to terminal-engaging position when the support reaches the desired group, and means actuated when the support reaches said stop means to hold said contact in terminalengaging position and move it into engagement with a desired terminal in the desired group.

20. In an electric switch, a plurality of groups of terminals, a contact to engage said terminals, a rotatable support on which said contact is movable, means to stop the support at the beginning of any desired group, means to move said stop means to position the same, means normally holding said contact out of engaging position with said terminals on movement of said support,

means to move said contact to terminalcngaging position when the support reaches the desired position, means actuated thereby to move the stop means still farther, and means to move said contact to and engage it with a terminal in the desired group.

21. In an electric switch, a power-driven shaft, a spring-driven wheel rotatably and longitudinally movable relative to said shaft, a contact movable in response to movement of said wheel, a plurality of terminals for engagement by said contact, means to control the escapemcnt of said wheel, means to engage said contact with one of said terminals, clutch means between said wheel and shaft operated on the relative longitudinal movement of said shaft and wheel, means to effect the relative longitudinal movement of said shaft and wheel, and means to disengage said clutch means on restoration of said wheel to normal position.

22. In an electric switch, a shaft, a member mounted on. said shaft, a support mounted on said member, a contact slidably carried by said support, a plurality of terminals arranged for engagement by said contact, means normally holding said eontaet out of tern'iinal-engaging position during the movement of the support, means to move said contact to terminal-engaging position, means to retain said contact in terminal-engaging position, and means operatcd on longitudinal movement of said member to disengage said retaining means.

23. In an electric switch, a rotatable support, a contact slidably mounted thereon, a plurality of groups of terminals arranged for engagement by said contact, a rotatable wheel, a spring connection between said support and wheel to cause said support to follow the movement of said wheel, a stop to normally effect registration of said support and wheel, means to escape said wheel to any desired group of contacts, means to normally hold said contact out of engaging position with said terminals on escapemcnt of the wheel, means actuated on movement of the wheel to move said contact to terminal-engaging position on registration of said wheel and support, means to effect further movement of the wheel on said registration, means to hold said contact in terminal-engaging position during such further movement to effect engagement of said contact with a terminal in a desired group, means to disengage said contact and terminal, and means to restore the switch to normal position.

In witness whereof, I hereunto subscribe my name this 12th day ofSeptember A, D.,

FRANK A. LUNDQUIST.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

